Scientists are playing a key role in understanding what is happening
on and under the surface of the Gulf oil spill, and JPL instruments
like ASTER, MISR and MODIS are helping to map the changes. This
false-color, high-resolution image of oil on the Mississippi River
Delta was taken by JPL’s ASTER instrument on May 24, 2010. The silver
is the oil against the light-blue water and the vegetation is red.

LA CA&#209ADA FLINTRIDGE – Government scientists don’t have a rule book to help them figure out just how much oil has spilled into the Gulf of Mexico since a rig exploded off the coast of Louisiana more than a month ago.

But thanks to some help from instruments operated by Jet Propulsion Laboratory, a team of scientists from NASA, the National Oceanic and Atmospheric Administration and the U.S. Geological Survey estimate 130,000 to 270,000 barrels of oil are on the surface of the Gulf, according to a report from the U.S. Department of the Interior.

“The numbers are rough but reasonable,” said Victor Labson, a USGS member on the national team of scientists. “The only way to describe this is science on the fly.”

On Thursday, President Barack Obama promised to hold energy company BP accountable for the oil spill and said his administration would do everything necessary to protect and restore the coast.

JPL instruments – especially AVIRIS, an infrared sensor flown in an aircraft high above the scene – have been especially important in the effort to determine how much oil is covering the surface of the Gulf and how thick it is.

It uses the same technology that helped NASA scientists find traces of water on the moon, Labson said.

AVIRIS isn’t the only instrument that NASA and JPL have been using to come up with ways to measure the size of the massive spill.

MISR, a nine-camera satellite that monitors weather conditions on Earth, also has been deployed.

The satellite is being used to help measure the thickness of the oil sheen, according to Dong Wu, principal research scientist at JPL working on the mission.

Finally there’s ASTER. Also a satellite, ASTER is run jointly by NASA and Japan, officials said.

It’s capable of measuring water surface temperatures from space, and turned its telescope toward the spill, according to Mike Abrams, who works on the project.

ASTER does a good job of determining how much warm oil is on the surface of the cold ocean, he said.

At the same time, another team is working undersea to figure out the rate that oil is spilling out in the Gulf.